The proposed longitudinal study investigates early sleep development and its relation to infant-mother interaction and neonatal medical risks in preterm/low birth weight (PT LBW) infants. This study, which is an extension of Dr. Poehlmann's NIH-funded R01, follows infants for 2 years and involves data collected at hospital discharge, 4, 9, and 24 months (corrected for gestational age). This extension has 3 specific aims, which are not addressed in the original grant: (1) to document the development of sleep patterns in PT LBW infants over the first two years of life, (2) to investigate infant-mother interaction quality as a mediator of the relationship between neonatal health risks and early sleep problems, and (3) to investigate whether early PT LBW infant sleep problems lead to less, optimal infant-mother interactions over time, thus amplifying infant sleep problems at 2 years. The proposed investigation will advance the field of child development by examining the longitudinal processes involved in the development of early sleep regulation and will extend our knowledge of (1) PT LBW infant sleep, (2) the interaction of infant-mother relations and infant sleep over time, and (3) how neonatal medical risks directly and indirectly relate to the development of sleep problems. [unreadable] [unreadable]